not movable and located in the skull--help keep joints cushioned and lubricated

muscles

produce body movement by pulling on bones when they contract--produce body heat when they contract

3 kinds of muscle tissue

skeletal, smooth, and cardiac

involuntary muscles

responsible for involuntary body activities such as heart contractions and peristalsis--you cannot control the actions of involuntary muscles

TWO EXAMPLES OF INVOLUNTARY MUSCLES

smooth muscle and cardiac muscle

smooth muscle

found in the walls of arteries and organs of the body--contraction of smooth muscle is controlled by the nervous system

cardiac muscle

found in the walls of the heart-causes the heart to beat

voluntary muscles

attach to the skeleton and can be controlled for locomotion

example of voluntary muscle

skeletal (striated) muscle

skeletal/striated muscle

are attached to the bones of the skeleton--bones and body parts are moved by the contraction of these muscles

how do skeletal muscles usually function?

in opposite pairs

extensor

one muscle of the pair of skeletal muscles, which extends (straightens) the limb

flexor

the other muscle of the skeletal muscle pair, which bends the limb

example of extensor and flexor pair

biceps and triceps of the upper arms
-bicep--flexor--located on the front of the upper arm--when the bicep contracts, the forearm is pulled toward the front of the shoulder, causing the arm to bend
-tricept-extensor--located on the back of the upper arm--when the tricept contracts, the arm straightens out

what causing muscles to contract??

when nerves direct impulses to muscles

where do muscles get the energy needed to contract?

comes from energy stored in chemicals such as glycogen

muscle fatigue

muscle cells will continue to operate even if they do not receive sufficient oygen for aerobic respiration, so they change to anaerobic respiration and produce lactic acid, which causes muscles to hurt and causes you to rest so taht your muslces can get oxygen again

what are tendons and ligaments composed of?

connective tissue

tendons

bands of dense tissue that connect muscles to bones

ligaments

tough bands of tissue that hold bones together at joints

fractures

broken bones

sprain

tearing or stretching of the ligaments that hold together the bone end in a joint

hernias

an organ or tissue sticks out through a weak area in the muscle or other tissue that usually contains it such as the abdominal wall. the cause is usually weakness and a bulge in the wall

arthritis

inflammation of joints--causes stiffness, swelling, soreness, or pain

osteoarthristis

a type of arthritis that results from wear and tear on the cartilage at the joints